package com.tencent.cloud.uikit.ui.widget;

import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;

import com.tencent.cloud.iov.util.ResourcesUtils;

/**
 * @author vinsonhuang
 * @date 2018/9/25
 */
public class IovDecoration extends RecyclerView.ItemDecoration {

    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
    private Drawable mDivider;
    private int mOrientation;

    /**
     * 分割线缩进值
     */
    private int mInset;

    /**
     * 是否绘制头部分割线
     */
    private boolean isDrawHeaderDivider = false;

    /**
     * 是否绘制最后一个item分割线
     */
    private boolean isDrawLastDivider = false;

    private Paint mPaint;

    /**
     * @param orientation layout的方向
     * @param drawable    引入的drawable的ID
     * @param inset       分割线缩进值
     */
    public IovDecoration(int orientation, int drawable, int inset) {
        mDivider = ResourcesUtils.getDrawable(drawable);
        mInset = inset;
        mPaint = new Paint();
        mPaint.setColor(Color.TRANSPARENT);
        mPaint.setStyle(Paint.Style.FILL);
        mPaint.setAntiAlias(true);
        setOrientation(orientation);
    }

    public void setOrientation(int orientation) {
        if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
            throw new IllegalArgumentException("invalid orientation");
        }
        mOrientation = orientation;
    }

    public boolean isDrawHeaderDivider() {
        return isDrawHeaderDivider;
    }

    public void setDrawHeaderDivider(boolean drawHeaderDivider) {
        isDrawHeaderDivider = drawHeaderDivider;
    }

    public boolean isDrawLastDivider() {
        return isDrawLastDivider;
    }

    public void setDrawLastDivider(boolean drawLastDivider) {
        isDrawLastDivider = drawLastDivider;
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent) {
        if (mOrientation == VERTICAL_LIST) {
            drawVertical(c, parent);
        } else {
            drawHorizontal(c, parent);
        }
    }

    private void drawVertical(Canvas c, RecyclerView parent) {
        final int left = parent.getPaddingLeft();
        final int right = parent.getWidth() - parent.getPaddingRight();
        final int childCount = parent.getChildCount();
        // 默认不绘制最后一个item分割线
        int count = childCount - 1;
        if (isDrawLastDivider) {
            count = childCount;
        }

        int top = 0;
        int bottom = 0;
        for (int i = 0; i < count; i++) {
            View child = parent.getChildAt(i);
            RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
            if (isDrawHeaderDivider && 0 == i) {
                //画item最上面的分割线
                top = 0;
                bottom = top + mDivider.getIntrinsicHeight();
                if (mInset > 0) {
                    c.drawRect(left, top, right, bottom, mPaint);
                    mDivider.setBounds(left + mInset, top, right - mInset, bottom);
                } else {
                    mDivider.setBounds(left, top, right, bottom);
                }
                mDivider.draw(c);
            }

            //画item下面的分割线
            top = child.getBottom() + params.bottomMargin;
            bottom = top + mDivider.getIntrinsicHeight();
            if (mInset > 0) {
                c.drawRect(left, top, right, bottom, mPaint);
                mDivider.setBounds(left + mInset, top, right - mInset, bottom);
            } else {
                mDivider.setBounds(left, top, right, bottom);
            }
            mDivider.draw(c);
        }
    }

    private void drawHorizontal(Canvas c, RecyclerView parent) {
        final int top = parent.getPaddingTop();
        final int bottom = parent.getHeight() - parent.getPaddingBottom();
        final int childCount = parent.getChildCount();
        // 默认不绘制最后一个item分割线
        int count = childCount - 1;
        if (isDrawLastDivider) {
            count = childCount;
        }
        for (int i = 0; i < count; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int left = child.getRight() + params.rightMargin;
            final int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    //由于Divider也有宽高，每一个Item需要向下或者向右偏移
    @Override
    public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
        if (mOrientation == VERTICAL_LIST) {
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
        } else {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        }
    }
}
